Mineral oil compoisition and improving agents therefor



Patented Jan. 16, 1945 MINERAL OIL COMPOSITION AND IM'PROV- ING AGENTS THEREFOR Orland M. Reiff and Howard D. Hal-tough, Woodbury, N. J., assignors to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York No Dr a'wing. Original application February 3, 1940, Serial No. 317,122, now Patent No.

2,280,039, dated April 14, 1942. Divided and this application June 5, 1941, Serial No. 396,720

11 Claims. (01. 252-51) This invention has to do in a general way with mineral oil compositions and is more particularly related to compositions comprised of mineral oil and a minor proportion of an added ingredient which will improve the oil in one or more important respects.

It is well known to those familiar with the art that mineral oil fractions refined for their various uses are in and of themselves usually deficient in one or more respects, so that their practical utility is limited even in the particular field for which they have been refined. For example, mineral oil fractions refined for use as lubricants have a tendency to oxidize under conditions of use with the formation of sludge or acidic oxidation products; also the lighter fractions such as gasoline and kerosene tend to oxidize with the formation of color bodies, gum, etc. In order to prevent the formation of these products and thereby extend the useful life of the oil fraction, it is common practice to blend with such oil fractions an additive ingredient which will have the efifect of inhibiting oxidation, such ingredients being generally known to the trade as oxidation inhibitors or sludge inhibitors, gum inhibitors, etc.

It is also the practice to add other ingredients I to mineral oil fractions for the purpose of improving oiliness characteristics and the wearreducing action of such mineral o-ils when they are used as lubricants, particularly when the oils are used for the purpose of lubricating metal surfaces which are engaged under extremely high pressures and at high rubbing speeds.

Other ingredients have been developed for the purpose of depressing-the pour point of mineral oil fractions which have been. refined for use as lubricants, such refinement leaving 'acertain amount of wax in the oil, which, without the added ingredient, would tend to crystallize at temperatures which would render the 'oil impracticable for use under low temperature conditions. Additive agents have also been developed for improving the viscosity index of lubricating oil fractions.

for the ordinary lubricatingcil fractions to form,

under such conditions of use, carbonaceous deposits which cause the piston rings to become stuck in their slots and which fill the slots in the pil ring or rings, thus materially reducing the efllciency of the engine. Ingredients have therefore been developed which, when added to the oil, will reduce the natural tendency of the oil to form deposits which interfere with the function of the piston rings.

Aside from the corrosive action which attends the formation of acidic products of oxidation in mineral oil fractions of the lubricant range, it has been discovered that certain types of recently developed hard metal alloy bearing metals, such as cadmiiunesilver alloy bearings, are attacked by ingredients in certain types of oils, particularly oils of highviscosity index obtained by various methods of solvent-refining. This corrosive action on alloys of the above type has led to the .development of corrosion inhibitors which may be used in solvent-refined oils to protect such bearing metals against this corrosive action.

In the lighter mineral oil fractions, such as those used for fuel purposes, particularly in internal combustion engines, it has been found that the combustion characteristics of the fuel may be controlledand improved by adding minor proportions of various improving agents thereto.

Thevarious ingredients which have been developed for use in mineral oil fractions to improve such fractions in the various respects enumerated above are largely specific to their particular applications, and it has therefore been the practice to add a separate ingredient for each of the improvements which is to be efiected.

It is a primary object of the present invention to provide a mineral oil composition which has been improved in one or more of the various properties enumerated above by the incorporation therein of a small quantity of a multifunc- 40 tional compound selected from the group or class 'of metal-free organic compounds which is herein referred to generically as the oil-soluble or oilmiscible nuclear alkyl-substituted amino-aryl hydroxides or nuclear alkyl-substituted amino phenols in which a hydrogen of the amino group is replaced by the radical .of an oxyacid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly. to the aryl nucleus and the term "phenols" being used in its broadest generic sense, that is to say the term phenols includes both monoand poly-cyclic hydroxyaromatic compounds. The radical of an oxyacid as just defined above is sometimes referred to herein as an oxyacidyl radical and the amino group (-NH2) in which a hydrogen is replaced by such a radical is hereinafter referred to'for convenience as an oxyacidyl-amino group or as an "N-esterifled group. These oil-miscible nuclear alkyl-substituted oxyacidyl-amino-aryl hydroxides should, of course, be substantially stable toward the mineral oils when intimately admixed therewith.

We have discovered that oxyacidyl-amino aryl hydroxides or oxyacidyl-amino phenols of the generic class above referred to may be added in small quantities to mineral oil fractions to form mineral oil compositions or blends superior to the unblended fractions in one or more important respects, and the present invention, therefore, is broadly directed to a mineral oil composition containing a compound falling into the general class referred to.

The oil-improving agents contemplated by this invention are all characterized by the presence of an aromatic nucleus in which at least one nuclear hydrogen has been substituted with an hydroxyl group and in which another nuclear hydrogen has been substituted with an oxyacidylamino radical or group. This characterizing group may be represented by the formula T (OH) (N) in which T represents an aromatic nucleus; (OH) represents at least one hydroxyl group and (N) represents an oxyacidyl-amino radical or group, the (OH) group and the (N')- group each being attached to the nucleus T).

The unsubstituted amino-aryl-hydroxides corresponding to the group represented by the above formula, in which the amino group contains only hydrogen and'which are otherwise unsubstituted are not miscible with mineral oil, and it is therefore important that the improving agents containing the above characterizing group have additional nuclear or an amino hydrogen, or both, replaced with substituents of an oil-solubilizing nature. Preference is given to compounds of the above type in which at least one nuclear hydrogen has been replaced with an oil-solubilizing substituent since such compounds also impart or tend to impart multifunctional properties to the compound when mixed with refined petroleum distillates. By the terms oil-miscible or oil-soluble as they areused herein we have reference to that property of remaining uniformly dispersed in the mineral oil fraction either as a true solution or as a colloidal suspension during normal conditions 'of handling and use.

The improving agents contemplated by this inand the pour point as well as other important properties of viscous mineral oils.

As a general proposition, therefore, it may be said that the improving agents contemplated by this invention are nuclear alkyl-substituted oxyacidyl-amino-aryl hydroxides, herein termed C- alkyl oxyacidyl amino-phenols, having the characterizing group T'(OH) (N) described above, in which additional nuclear hydrogen is replaced with an oil-solubilizing substituent such as a predominantly aliphatic material, such substituent comprising a suflicient proportion of the composition as a whole to render the same miscible with mineral oil fractions undernormal conditions of handling and use. As a further generalization it may be said that at least one point on the aromatic nucleus T, and preferably two or more points on such nucleus, are substituted with allphatic hydrocarbon radicals or groups, such allphatic radicals or groups preferably being high molecular weight derivatives or heavy alkyl groups.

The simplest type of compound satisfying the above preferred requisites may be represented by the formula:

in which R represents at least onealiphatic hydrocarbon radical or group, such group or groups preferably corresponding to relatively high molecular weight aliphatic hydrocarbons and being attached to a monoor polycyclic aromatic nucleus T and in which (OH) and (N) are as indicated above, the (N) group being preferably an oxyacidyl amino group in which the oxyacidyl group is derived from an inorganic acid, herein vention are characterized by the presence of alkyl substituents or aliphatic radicals in the aryl nucleus, and the improving agents preferred for use in 'viscous mineral oils are further characterized by the presence of alkyl or aliphatic substituents in the aryl nucleus which will give other properties to the composition as a whole in addition to the oil-miscibility. We have found, for example, that where the aryl nucleus is substituted with one or more aliphatic groups corresponding to certain aliphatichydrocarbon compounds of relatively high molecular weight (herein referred to as heavy alkyl groups), a compound or composition can be obtained which will effect marked improvement in the viscosity index.

termed an inorganic-oxyacidyl-amino group.

As indicated above, the preferred type of compounds contemplated by the present invention are those represented by Formula 1 i i/which the group represented by R is an aliphatic hydrocarbon radical of relatively high molecular weight, preferably containing not less than 20 carbon atoms and in which the substituent represented by (N) is an inorganic oxyacidyl amino group, the latter type of compounds being hereinafter referred to as inorganic oxyacidyl-amino phenols. As also previously indicated, the compounds in which the group represented by R is a heavy aliphatic hydrocarbon radical, are preferred because of their greater oil solubility and also because such heavy aliphatic hydrocarbon radicals impart multi-functional activity to the compound or reaction product when combined with mineral oils, particularly lubricating oils.

In addition to the aliphatic or alkyl substituent R, the compounds or compositions contemplated herein as mineral oil improving agents may have additional nuclear hydrogen replaced with other substituents which may or may not have a solubilizing efi'ect upon the composition as a whole. Such a'compound in its simplest form may be represented by the formula:

in which R, T, (0H) and (N) have the same significance indicated above and in which Y represents residual hydrogen which may be replaced by a radical selected from the group consisting of hydroxy, chlorine, alkoxy, aroxy, aralkyl, alkaryl,

aryl, nitro, amino, keto, nitroso, diazo, azo, ether dl-, and tricyclic nuclei are illustrated by the following speciflc formulae:

. R R R in which (OH) and (N') have the same significance indicated above and at least one R represents an aliphatic radical or group, preferably a heavy alkyl group, and in which the remaining Rs represent residual hydrogen which may be replaced with hydroxy, chlorine, alkoxy, aroxy, aralkyl, alkaryl, aryl, nitro, amino, keto, nitroso,

diazo, azo, ether alcohol and ester radicals or groups.

In the foregoing examples it will be observed that the aliphatic or alkyl substituent in the aryl I nucleus is a monovalent aliphatic hydrocarbon group, but, as will appear from the hereinafter described synthesis of our preferred type of oilimproving agent, part or all of the aliphatic hydrocarbon material may be comprised of polyvalent aliphatic hydrocarbon radicals or groups in which the several valences are attached to separate aromatic nuclear groups. Compounds of this type are included under the following general formula representation:

in which T, (H) and (N') have the same significance indicated above; R" rep-resents at least one aliphatic or alkyl radical or group, such alkyl group or groups being attached by one valence only to at least one aromatic nucleus T, v representing the valence of the aliphatic radical R, which may be one toffour; Yb represents a monovalent element or group selected from the class identified above in connection with Y b repretwo, three, or four) or since R" is defined as being at least one aliphatic radical or group and may therefore include several such groups, it will be seen that this general Formula 111 is inclusive of compounds having nuclear aliphatic groups or groups radicals of different valences (from one to four) in the same molecule. Also it will be observed that since n may be any whole number from one to four, the number of aromatic nuclei T- in the molecule may likewise vary from one to four. It will be seen, therefore, that the relationship between 11. and v in Formula III, in its broadest aspect, is such that when n is equal to one, u is equal to one; and when n is greater than one, the valence v of at least one of the R's is equalto n (in order to tie the several nuclei or Ts together) the valence of any remaining Rs being any whole number equal to or less than 11.

.A stated above, and as will appear more fully later from the description of their synthesis, these materials represented by general Formula III may contain both monovalent and polyvalent aliphatic substituents in the nucleus. Both the polyvalent aliphatic substituent and the monovalent substituent, if both are present, may be introduced 'in the nucleus as part of an alkylation reaction,

or all or part of the monovalent aliphatic substituent may be present in the nucleus of a hydroxyaromatic starting material as low molecular weight aliphatic groups, such as methyl, ethyl, p pyl groups, etc.

' Compounds of the general type last described the nuclear aliphatic substituent i monovalent (v=l and n=1) or in which all of the aliphatic substituent is polyvalent (v and n being equal to.

above, which include polyvalent substituted aliphatic substituents and may also include both the monovalent and the polyvalent aliphatic substituents. are included under the sub-generic formula representation.

dicates the same group of substituents as described above for Y; RC represents monovalent aliphatic radicals or groups; b represents the number of Ybs and is equal to zero or a whole number corresponding to the valences on the.

nucleus T not satisfied with R (OH), (N') and Re; 0 indicates the number of Rcs and is equal to zero or a whole number corresponding to the valences on the nucleus T not satisfied with R (0H), (N') and Yb; and n represents a whole number from two to four and indicates the total number of the groups (T(OH)(N')Yb Rc) present in the molecule represented by the formula which are attached to the aliphatic group or groups represented by R through the valences 12'.

In the above general Formulae III and IV it will be understood that since R and R are aliphatic hydrocarbon radicals of the chain type and are each attached by one valence only to each corresponding aromatic nucleus, the valence v or v of such radical or radicals is of necessity never greater than the number n, which indicates the number of aromatic nuclei in the molecule and in Formula III isalways equal to one when n equals one. Otherwise an R or an R having a valence greater than the number (n or n) of aromatic A simple type of compound coming under general Formula III in which 1) and n is equal to one and in which there is only one oil-solubilizing aliphatic group, R, may beillustrated by the following formula showing T, for purposes of illustration, as a monocyclic nucleus:

A OH N H H i -C CH Inthe above formula the chain represents the oil-solubilizing alkyl substituent- (R and Yb, N' and (OH) have the same significance as has been heretoforegiven to these groups.

Since group R has been defined as at least one, it will be apparent that there may be more than one heavy alkyl substituent attached tothe nucleus T, such a compound, where v and 'n are each one and in which there are two such monovalent R groups, may be represented by the following formula:

in which the chains and the substituent characters have the same significance defined above. Compounds of the type satisfying the general ormula III and the sub-generic Formula IV in which R (or R is polyvalent and v (or v) and n (or n) are more than one and in which there is only one such polyvalent B group, may be illustrated by the following formula, in which the aryl nucleus T is again indicated for illustration as being monocyclic:

0 OH 03 OH Y m-N Y 5-bp Y flN' H R. R. c H 11c-c o c on H H H H H a n C OH on n R. n C CH 11 H I The probable molecular structure of compounds in which the aryl nucleus T is polycyclic will be obvious from the foregoing exemplary Formulae A to D inclusive, and the molecular structure of compounds in which 1: and n are equal to two and Gil As to the possible number of R" andv (Re) groups going to make up a single molecule, this will vary with the extent to which itis desired to effect substitution of the nucleus with oil-solubilizing aliphatic groups for obtaining thedesired properties in the product and is, of course, limited by the number of valences on the aromatic nucleus which are available for substitution.

As will be apparent to those skilled in the art, the maximum possible number of R" (and RC) groups which can be attached to a single aromatic nucleus will vary as the nucleus is mono or polycyclic and also as the nucleus is otherwise substituted. It will also be apparent that available valences on the nuclei may all be attached to polyvalent aliphatic substituents.

It will be understood that the oil-improving agents contemplated by this invention may be pure compounds satisfying the general Formula III described above with any one of the various mono and poly cyclic aromatic nuclei as T and the various substituents (R (or R"'), (N') and Y) described, the only requisites being that at least one nuclear hydrogen be substituted with an oxyacidyl-aniino, another nuclear hydrogen be substituted with a hydroxyl group and at least one nuclear hydrogen be substituted with an oilsolubilizing aliphatic radical or group, However, in manufacturing the preferred oil-improving product of the present invention by the preferred method of procedure, as will appear more fully later on, the final oil-improving product obtained is normally or usually a mixture of different compounds corresponding to different values of n and v and to different numbers of aliphatic groups R.

As has been emphasized hereinabove, it is important that the preferred oil-improving agents asrepresented by general Formulae III and IV have nuclear hydrogen in the aromatic nucleus T substituted with predominantly aliphatic material which comprises a suflicient proportion of the composition as a whole, particularly when N contains no aliphatic organic acyl radical, t render the same miscible with the mineral oil fraction in which the improving agent is 'used under normal conditions of handling and use. It appears from the results of our research that there is a critical range in' the degree of alkylation of these improving agents below which the or agent will not satisfy the requirements miscibility. Expressing this -in another product for Oilway, it

appears that the hydroxyaromatic constituent from which the oxyacidyl-amino-aryl hydroxide is derived should not exceed a ce ain percentage of such alkylated hydroxyaromatic composition as a whole. This critical range of alkylation may be roughly" expressed as the ratio by weight of (T(OH)) to R(T(O H))n.

The degree of alkylation and the critical range within which operative or preferred compounds can be obtained may also be expressed as the number of carbon atoms contained in the aliphatic substituents for each aryl nucleus in a given molecule or molecular structure.

The critical range in the degree of alkylation, as defined above, of the aryl nucleus in the improving agents contemplated herein may vary with: (a) the mineral oil fraction in which the improving agent is to be used; (b) the aryl nucleus T (monoor polycyclic) (c) the hydroxyl content of the-aryl nucleus from which the oxyacidyl l amino-aryl hydroxide is derived (monoor polyhydric); (d) the character of aliphatic material comprising the substituent (straight or branched chain) (e) monoor poly-substitutionof the aryl nucleus; and (f) other substituents on the nucleus T, which may be of positive or negative or of neutral solubilizing activity.

In general it may be said that a polycyclic nucleus appears to require a higher degree of alkylation than a mono-cyclic nucleus; that a polyhydric nucleus requires a higher' degree of alkylation than a 'monohy'dric nucleus; and that branched chain aliphatic substituents have a somewhat greater solubilizing action than straight chain solubilizing substituents.

In view of the foregoing variables it would be impracticable and probably misleading to attempt to give an expression and figure which would indicate accurately the proper ratio of hydroxyaromatic constituent to the alkylated hydroxyaromatic constituent which would express a de gree of aliphatic substitution satisfying all cases taking these variables into account. As a guide for preparing these improving agents, however, our research indicates that for a product having pour depressingand V. I. improving properties in addition to other valuable properties the ratio, expressed as: I

should not be greater than 0.17 when the weight of'the hydroxyaromatic nucleus or component (T(OH))11 is expressed in terms of its chemically equivalent weight of phenol (CsHsOH). However, for mere oil-solubility with inhibition of oxidation we have found that this ratio may be raised as high as .60 or even higher by substituting the nucleus with branched chain aliphatic groups or by including an aliphatic acyl radical in the N group. In general it may be said that in the preferred improving agents contemplated herein, the ratio by weight of. the hydroxyaromatic component in the product to the corresponding alkylated hydroxyaromaticnucleus or component therein should not be greater than about seventeen parts by weight of the former to about 100 parts by weight of the latter, or about seventeen per cent, when the weight of the hydroxyaromatic nucleus or component is expressed in terms of its chemically equivalent weight of phenol. It will be observed that the ratio as as a Working guide for the preparation of oilsoluble materials and the preferred multifunctional materials. I

As stated above, the degree of alkylation may also b expressed by the number of carbon atoms contained in the aliphatic substituent for a given hydroxyaromatic nucleus T. As a general guide here it may be said that the aliphatic substituents represented by R in the above general Formula III should, for the preferred multifunctional materials contemplated herein, contain at least thirty carbon atoms for each aromatic nucleus T.

Th ratio of seventeen per cent, which we may a term the phenolic ratio, represents what we consider a maximum'figure for the preferred products contemplated herein, and in general it will be found that this figure will be lower, the actual ratio, of course, being dependent upon the variable factors enumerated above. For example,

as will later appear, an improving agent of thepreferred type inwhich the aliphatic substituent in the aryl nucleus is derived f1 om petroleum wax (a predominantly straight chain aliphatic hydrocarbon of at least twenty carbon atoms) and in which the aromatic nucleus was derived from phenol otherwise unsubstituted may have a phenolic ratio, as expressed above, not substantially reater than about thirteen per cent.

A further general guide for the synthesis of the preferred improving agents for viscous oils is to alkylate the aromatic nucleus so it is poly-substituted with aliphatic hydrocarbon radicals or groups preferably of relatively high molecular weight.

As has been previously indicated, it is one of the primary objects of the invention to provide an oilimproving agent which will have multi-functional ment in viscosity index and pour point in addi-.

- tion to other properties to be hereinafter pointed v of nuclear hydrogen in a nuclear-alkylated hy- Represented by the Formula VII above does not a hydroxyl group; but, since the aliphatic substituent is primarily relied upon in the agents contemplated herein as the solubilizing and multifunctional-producing substituent, is is believed that the foregoing expression and limits will serve *droxyaromatic compound with an amino (NHz) or oxyacidyl-amino group as will be more fully explained further on.

The general procedure indicated above for preparing the oil-improving agents of the present invention has shown an alkylated or an aliphaticsubstituted hydroxyaromatic compound as the starting material. Compounds of this nature, which satisfy the requirements of high alkylation for the preferred improving agents discussed above, or mixtures of such compounds can 'be readily prepared by' alkylating a monoor polycyclic, monoor polyhydric, substituted or unsubstituted hydroxyaromatic compound with aliphatic compounds or predominantly aliphatic materials. 7

The starting material for the hydroxyaromatic constituent in the alkylation reaction to obtain an alkylated hydroxyaromatic product in which Yb, if present, is residual hydrogen, may be a monoor polycyclic hydroxyaromatic compound otherwise unsubstituted; or such compounds containing alkyl substituents; or in certain special cases (to be hereinafter described) the starting material may be an alkyl-aryl ether or an aralkyl-aryl ether. For obtaining an alkylated hydroxyaromatic product containing a I Y substituent, in addition to or in place of residual hydrogen, the starting material for the I hydroxyaromatic constituent may be a monoor polycyclic hydroxyaromatic compound in which part of the nuclear hydrogen is substituted with a member or'members of the group consisting of chlorine, hydroxy, alkoxy, aroxy, aryl, alkaryl, and aralkyl groups. 1

Examples of the hydroxyaromatic compounds which may be used as starting material for the alkylation reaction are: phenol, resorcinol, hydroquinone, catechol, cresol, xylenol, hydroxydiphenyl, benzylphenol, phenyl-ethyl-phenol, phenol resins, methyl-hydroxydiphenyl, guaiacol, alphaand beta-naphthol, xylyl naphthol, benzyl naphthol, anthranol, phenyl methyl naphthol, phenantrol, anisole, beta-naphthyl methyl ether, chlorphenol, and the like. Preference in general is to the monohydroxyphenols otherwise unsubstituted, particular preference being given to phenols and alphaand beta-naphthol.

The alkylation of 'the hydroxyaromatic compound may be accomplished in various ways, such as by a Friedel-Crafts synthesis, using a halogenated aliphatic hydrocarbon, or by reaction with unsaturated high molecular weight aliphatic compounds or higher alcohols in the presence of H2804 as a catalyst.

We have found the Friedel-Crafts type of alkylation reaction to be particularly adapted to the step of preparing the alkylated hydroxyaromatic compounds from which the improving agents described herein-are synthesized because it afiords a convenient means of controlling the degree of alkylation and obtaining the desired "phenolic ratio" for use in the preferred mineral oil composition contemplated by this invention.

In this reaction an appropriate monoor polychlorine-substituted aliphatic compoundor material is reacted with the desired hydroxyaromatic compound in the presence of a catalytic amount of aluminum chloride. Pure or substantially pure monoor polychlorine-substituted aliphatic compounds may be used. However, as will be readily understood by those skilled in the art, since it is usually very diflicult to prepare or obtain high molecular weight aliphatic hydrocarbons in a pure or substantially pure state and since it is equally diflicult to prepare the chlorine (or other halogen) substitution products of such hydrocarbons in a pure or substantially pure state, we prefer to employ a mixture of such hydrocarbons, such as a suitable petroleum fraction, as the starting material for our preferred improving agents, converting it into a mixture of different chlorine (or other halide) substitution products by any suitable method for use in t he alkylation step. In general it may be said that the high molecular weight aliphatic hydrocarbons contemplated by this invention as preferred sources for the alkyl or aliphatic substituent R in Formula 111 above may be pure or mixed compounds typified by those which characterize the heavier products of petroleum, such as heavy petroleum oils of the lubricant type, petrolatum andv crystalline petroleum wax or other compounds or materials which will result in relatively long chain aliphatic substituents. Special preference is given to petroleum wax of melting point not substantially less than about F. Such specially preferred aliphatic hydrocarbon materials commonly have molecular weights of about 250 and have at least twenty carbon atoms in their molecules.

As stated above, the Friedel-Crafts synthesis aifords a convenient means of controlling the degree of alkylation of the product. This is accomplished by controlling: (a) the chlorination of the aliphatic hydrocarbon and (b) the reacting proportions of the chlorinated aliphatic hydrocarbon and the hydroxyaromatic compound used in the Friedel-Crafts reaction. As is well known to those skilled in the art, the replacement of nuclear hydrogen in the hydroxyaromatic compound with an aliphatic group is, in the Friedel-Crafts synthesis, effected by reaction of such nuclear hydrogen with chlorine in the chlorinated aliphatic compound, the substitution being effected with evolution of HCl. It will thus be seen that the number of chlorine substituents in a chlorinated aliphatic compound corroesponds to the number of valences (v in general Formula III) which will be satisfied by or attached to hydroxyaromatic nuclei in the product of the reaction. For example, in a reaction where a quantity of pure monochloraliphatic hydrocarbon containing say three atomic proportions of chlorine is reacted with one molecular proportion of hydroxyaromatic compound, the resulting alkylated product corresponding to the constituent represented by RlJ(T(OH)Yb)n in general Formula III is one in which '0 and n are equal to one and there are three aliphatic groups R attached to one nucleus T. On the other hand, assuming a reaction in which a quantity of pure trichlor-aliphatic hydrocarbon containing three atomic proportions of chlorine is reacted with one molecular proportion of hydroxyaromatic compound, the product would be one in which 0 and n of general Formula III are each equal to three, and the solubilizing action of a single aliphatic group would be distributed among three nuclear hydroxyaromatic groups. It is due to this latter condition that we consider it preferable that the number of valences v (in R" of Formulae III, etc.) be maintained within the range of from one to four hereinabove specified. In other words, it appears that the required oil-solubilizing and oil-improving action of the aliphatic substituent Rv, particularly where the agent is to be used for multifunctional activity in viscous oils, is notobtained with materials predominantly compriser of a compound or compoundsi-corresponding to the constituent represented by R." (T(OH)Yb)n in Formula III in which 12 and n are greater than four. Hence, for use in the Friedel-Crafts reaction the chlo= rinated high molecular weight aliphatic material should be a compound, or should be predominantly comprised of compounds, in which the chlorine content is not greater than a tetrachlor compound.

As will be readily apparent to those skilled in the art, the chlorination of an aliphatic material such as a liquid petroleum fraction or a crystalline petroleum wax will normally or usually result in a mixture of monoand poly-chlor-aliphatic hydrocarbon compounds. Consequently,

the product of a Friedel-Crafts reaction between such chlorinated material and a hydroxyaromatic compound will be a mixture of different compounds corresponding to different values of v and n in the formula R. (T(H)Yb)n and the final oxyacidyl amino-aryl hydroxide derived therefrom will likewise be a mixture of compounds corresponding to different values of n and v in the constituent represented by R (T(OH)Y1 n in general Formula III. It will be understood, therefore, that the specific values for v and n in the above formula, as well as the formula itself, relate to the different specific compounds present in such a mixture which characterize it as a product of the present invention.

However, in the case of a pure compound corresponding to general Formula III or in mixtures thereof, we have, as previously stated, discovered that for a satisfactory product, the ratio by weight of hydroxyaromatic component (T(OH) )1. to the corresponding alkylated hydroxyaromatic nucleus or component (R"(T(OH) )1) should not be greater than a certain critical maximum ratio which varies with constituents, conditions of use, and properties desired, as discussed in detail hereinabove.

The above-mentioned ratio of hydroxyaromatic component to the corresponding alkylated hydroxyaromatic component,

in which the hydroxyaromatic component is calculated as phenol and which is therefor herein referred to as the phenol content or phenolic ratio, is usually calculated from the weight of the hydroxyaromatic compound used up in the alkylation reaction and from the total weight of alkylated compound resulting from such alkylation reaction, as will be readily understood by those skilled in the art.

For example, when the Friedel-Crafts synthesis is used for alkylation, the aliphatic hydrocarbon material is first chlorinated until the weight of phenolic ratio desired. After the Friedel-Craftsreaction and purification of the product the weight of aliphatic material in the chlorinated aliphatic starting material is subtracted from the weight of the alkylated or aliphatic-substituted.

product to obtain the weight of hydroxyaromatic material ((T(OH) )n) actually combined or used up in the alkylation synthesis. From this value and the weight of the alkylated product (R"(T(OH) )1) the phenolic ratio or phenol content can be readily calculated. If there are other-substituents (Yb) on the hydroxyaromatic nucleus in addition to ing the phenolic ratio, an operation which will be apparent to those skilled in the art.

In the foregoing description of the Friedel- Crafts alkylation reaction we have referred to a hydroxyaromatic compound as a starting material. This same reaction may be used with an alkyl-aryl ether or an aralkyl-aryl ether which undergoes a substantial rearrangement during Friedel-Crafts alkylation to form an alkylated hydroxyaromatic compound in which the alkyl group of the ether replaces one of the nuclear hydrogen atoms.

In the event it is desired to obtain a'product R (T(OH)Yb)n which contains an alkoxy group as the substituent Yb, it is preferable that the alkylation be effected with a hydroxyaromatic compound containing such alkoxy or aroxy group as a substituent and a high molecular weight unsaturated aliphatic hydrocarbon (such as polymerized isobutylene, dodecylene, tetradecylene, octadecylene, melene, etc.) or a higher alcohol (such as cetyl alcohol, myricyl alcohol, ceryl alcohol, etc.) using H2504 as a catalyst. By this procedure, the hydroxyaromatic ether can be al kylated without substantial rearrangement taking place. As an alternative procedure, polyhydric phenols can be nuclear alkylated by reaction with alcohols or unsaturates or by Friedel-Crafts reaction followed by substitution of the hydroxyl hydrogen of one hydroxy with a low molecular weight alkyl group. In carrying out this latter procedure, alkylated polyhydric phenol is treated with an alkali alcoholate to introduce alkali metal into the OH group followed by treating with the desired alkyl halide, whereby the substitution is effected.

When it is desired to obtain a keto group as the Yb" in general Formula III, the alkylated hyaction by methods well-known to those skilled in the monoor poly-valent aliphatic groups, a deduction should be made for them before calculatthe art.

'A nitro group can be introduced by dinitrating the alkylated hydroxyaromatic compound, followed by selective reduction .of only one nitro group, such as can be carried out by the ammonium sulfide method of reduction. i

NITRATION OF ALKYLATED HYDROXYARO- MATIC COMPOUNDS The above mentioned alkylated starting material may be readily converted, into the cor-.

cedure may be carried out as illustrated by the following example:

EXAMPLE I Reaction mixture t-Amyl phenol (hydroxy-benzene) -mol 1 Benzol litre- V3 17.5% by weight H20 {1 part HONa-3 parts H2O 2 Procedure REDUCTION OF ALKYLA'I'ED .NITROHY- DROXYAROMATIC COMPOUNDS EXAMPLE II p-tert. Amyl nitrophenoLs mol 1 I Tin metal mols 3 Cone. hydrochloric acid litres 1.5

The amyl nitrophenol and the tin are mixed together, thereafter adding the HCl in 250. cc. portions With stirring over a'period of one hour.

The reaction temperature is then raised to the boiling point and the mixture refluxed until all the tin has reacted and all the amyl nitrophenol has been reduced, which is indicated by its complete solution in the hot mixture.

The reaction mixture is then cooled, whereupon the amyl amino-phenol hydrochloride precipitated as a solid compound. The precipitate is filtered oif and redissolved in one liter of water and freed of tin chlorides by passing in HzS gas. The tin sulfides are filtered oil. and while still hot, concentrated hydrochloric acid is added to the reaction mixture until a permanent cloudiness appears, whereupon the material is set aside to cool., The compound obtained as the hydrochloride is a white to light yellow crystalline product.

Dueto the susceptibility of alkylated aminohydroxyaromatic compounds to oxidation in the air it has'been advisable to store them in the form of the hydrochloride. Where it is desired to obtain the corresponding basic compound free, the proper amount of the hydrochloride is added to a non-aqueous solvent'and neutralized with ammonia gas. A concentrated blend of the free alkylated aminohydroxyaromatic compound can be made in mineral oil in this manner.

PREPARATION OF NUCLEAR AIKYLATED OXYACIDYL AMINO HYDROXYARO- MATIC COMPOUNDS When nuclear alkyiated, the amino-hydroxyaromatic compounds may also be N-substituted with oxyacidyl substituents forming oil-soluble derivatives. The following methods can be used for the introduction of N-substituents.

N-ESTERIFICATION WITH O'XYACIDYL GROUPS used in the formation of the N-ester (or oxyacidyl) product, the reaction may be represented by the following generalized equation:

AOH POCla U U R R C I Q 0 1 I l H t l H,

and wherein the ring nucleus represents mono or polycyclic aromatic nuclei.

Examples of acid chlorides of the inorganic acids of non-metallic or acidic metalloid elements that may be used in the N-esterification reaction mentioned above are the following: P0013, BCh, SiCh, PCla, S012, SeClz, TeClz, as well as the corresponding bromides and iodides.

In general, as previously indicated, any acid chloride or anhydride of an inorganic acid may be employed in the N-esteriflcation reaction which forms an N-esterified (oxyacidyl) reaction product which is substantially stable toward mineral oils when intimately admixed therewith. I

Representative examples of the organic acid anhydride or acyl halides which may be used for this purpose are the anhydrides and acyl halides of the following organic acids:

(1) Saturated aliphatic mono carboxylic acids ranging from acetic to montanic acid.

(2) Unsaturated aliphatic monocarboxylic acids such as acrylic, oleic, olaidic, crotonic, etc.

(3) Saturated .aliphatic polycarboxylic acids such as succinic, oxalic, adipic, sebacic, etc.

(4) Unsaturated aliphatic polycarboxylic acids such as maleic and fumeric acids.

(5) Substituted mono and polycarboxylic aliphatic acids containing hydrogen, hydroxyl, amino, ether or keto groups such as chloracetic acid, hydrcxystearic acid, tartaric acid, glycollic acid, octyloxyacetic acid and pyroracemic acid.

(6) Aromatic monocarboxylic acids such as benzoic and naphthoic acids.

(7) Aromatic polycarboxylic acids such as phthalic acid.

(8) Alkylene-substituted aromatic monocarboxylic acids such as cinnamic acid.

(9) Aryl substituted mono and polycarboxylic aliphatic acids with carboxyl in the said chain such as phenylstearic, naphthyl stearic and naphthyl polystearic acids.

(10) Substituted aromatic mono and polycarboxylic acids containing halogen, hydroxyl, amino, alkyl, aryl, aralkyl, keto, nitro, or alkoxy in the nucleus, such as chlorbenzoic, salicyclic, anthranilic, toluic, phenyl-benzoic, benzoylbenzoic, nitrobenzoic and anisic acid.

(11) Non benzenoid cyclic mono and polycarboxylic acids such as abietic and camphoric acids, and heterocyclic carboxylic acids such as furoic acid.

Of the above organic acylating agents, those corresponding to the saturated aliphatic and aromatic acids are preferred. In most cases, compounds of higher V. I. can be prepared by use of the dibasic acid chlorides because of the formation of more resinous products thereby.

Also while the present invention in its preferred form is directed primarily to the above mentioned metal-free nuclear alkylated oxyacidyl-amino hydroxides, it is also directed to, and is considered by us to be inclusive of the closely related corresponding metal-free nuclear alkylated oxyacidylamino-hydroxyaromatic compounds in which the hydrogen of the hydroxy group has also been replaced with an oxyacidyl group, preferably the oxyacidyl radical of an oxy-acid of phosphorus. When such a substitutedhydroxy group is also desired (which is preferred), an additional equivalent of acid halide or acid anhydride must be employed over and above that which may be required to substitute the amino group containing replaceable hydrogen, such amino groups, as is.

, negative element or so-called acidic metalloid in place of the metal in the corresponding wellknown metal-chelate type compound, as illustrated in the reaction represented by the following exemplary equation:

(c) OH Pooh R I P=O+3H0l il N Hz N Any of the other acid halides mentioned above may be substituted for the POCla in the reaction represented by the above Equation 0, with the formation of other similar so-called acidic metalloid chelate type compounds as will be readily understood by those skilled in the art.

It is generally believed by those skilled in the art that in the formation of any of the above chelate-type, compounds the OH and amino groups must be inadjacent positions such as the ortho position.

PREPARATION OF WAX-S U B S T I T U T E D OXYACIDYL-AMINO-HYDROXYAROMATIC COMPOUNDS (l) ALKYLATION or PHENOL WITH PETROLEUM WAX until about one-sixth the Weight of the chlorwax formed is chlorine. Aquantity of chlorwax thus obtained, containing three atomic proportions of chlorine, is heated to a temperature varying from just above its melting point to not over 150 F., and one mole of phenol (CcHsOI-I) is ad-' perature of about 250 F. and then should be more slowly increased to about 350 F. To control-the evolution of HCl gas the temperature of the mixture is preferably raised from 250 F. to 350 F. at a rate of approximately one degree per minute, the whole heating operation occupying approximately two hours from the time of adding the aluminum chloride. If the emission of HCl gas has not ceased when the final temperature is reachedthe mixture may be held at 350 F. for a short time to allow completion of the reaction. But, to avoid possible cracking of the wax, the mixture should not be heated appreciably above 350 F., nor should it be held at that temperature for any extended length of time. It is important that all unreacted or nonalkylated hydroxy-aromatic material (phenol) remaining after the alkylation reaction be removed. Such removal can be effected generally by water-washing, but it is preferable to treat the water-washed product with super-heated steam, thereby insuring complete removal of the unreacted material and accomplishing the drying of the product in the same operation.

The wax-substituted phenol thus obtained may be characterized by the general formula in which R" represents at least one aliphatic group or radical characteristic of paraffin wax having a valence v of from one to four; T represents a monocyclic aromatic nucleus; Ya represents residual hydrogen, b being a number corresponding to the number of valences on the nucleus T not satisfied by R." and (OH); and n is a number from one to four corresponding to the valences v on the aliphatic group or groups R which are satisfied by the nuclear group or groups T(OH)Yb.

A wax-substituted phenol prepared according to the above procedure, in which a quantity of chlorwax containing three atomic proportions of chlorine (sixteen per cent. chlorine in the chlorwax) is reacted with one mole of phenol, may, for brevity herein, be designated as "wax-phenol (3-16). Parenthetical expressions of this type (AB) will be used hereinafter in connection with the alkylated hydroxyaromatic compounds to designate (A) the number of atomic propor-a tions of chlorine in chlor-aliphatic material reacted with one mole of hydroxyaromatic compound in the Friedel-Crafts reaction, and (B) the chlorine content of the chlor-aliphatic material. In the above example A=3 and B=16.

Wax-phenol (23-16) as obtained by the above procedure had a phenol content or a phenolic ratio" of about thirteen per cent. Our research indicates that this phenolic ratiov of thirteen per mixed therewith. The mixture is heated to about I 150 F., and a quantity of anhydrous aluminum chloride corresponding to about three per cent of-the weight of chlorwax in the mixture is slowly added to the mixture with active stirring. The

rate of addition of the aluminum chloride should.

be sufiiciently slow to avoid violent foaming, and during such addition the temperature'should be held at about 130 F. After the aluminum chloride has been added, the temperature of the mixture'may be increased slowly over a period of from fifteen to twenty-five minutes to a tem- (2) INTRODUCTION OF Ammo AND OXYACIDYL- Ammo ,GROUPS INTO WAX-SUBSTITUTED HY- DROXYAROMATIC COMPOUNDS (a) Introduction of'ami'no groups The introduction of an amino group into a wax-substituted hydroxyaromatic compound may be carried out by nitration followed by reduction in accordance with Examples I and II above (with only slight variations) which illustrate these two steps in the conversion of tertiary amyl phenol into the corresponding tertiary amyl aminophenol. These variations consist mainly in the use of a suitable solvent or diluent for the wax-substituted compound and other minor variations such as the us of zinc dust as reducing agent which will be readily understood, by those skilled in the art, from the followin example of the nitration step only of wax-substituted phenol:

EXAMPLE III-Nrranrrou 0F WAX PHENOLS Reaction mixture Wax phenol (3-16, 13.7% combined phenol) The sodium nitrate is dissolved in water and acidified with the cone. H2804, cooling to 120 F. and adding thereto the wax phenol dissolved in the Stoddard solvent. The temperature is allowed to rise to 140l60 F. during a one-hour period and then raised to 200 F. to complete the reaction. The mixture is cooled and all traces of acid removed by water-washing, thereafter removin the Stoddard solvent diluent .to Obtain the nitrated product.

The reduction of the nitro group of the end product of Example 111 above may be carried out as already stated in accordance with the reduction method of Example II with use of a. solvent and other variations similar to those indicated in Example 11 (2) (a).

INTRODUCTION or OXYACIDYL-AMINO GROUPS mro NUCLEAR Wax-Sussrrroran Ammo-Hximoxv- AROMATIC COMPOUNDS After introduction ofan unsubstituted amino group (NHi)' into the nuclear wax-substituted hydroxyaromatic compounds by nitration and reduction as described above the unsubstituted amino group may be N-substituted with oxyacidyl groups as previously described.

By following the above procedures several examples of wax-substituted oxyacidyl-amino phe 11015 in which the oxyacidyl group is derived from an inorganic acid have been prepared, as follows:

Phosphorous amide of wax aminophenol (3-16).

Silicon amide of wax aminophenol (3-16).

Phosphite ester of phosphorous amide of wax amino-phenol (3-16).

In some instances where the final product is highly viscous or waxy it is sometimes desirable to use diluents in the preparation of the compounds for the purpose of reducing the viscosity of the mixtures. In the event the compounds are being prepared for incorporation in a particular oil it is convenient to employ as a diluent a quan-' tity of the same oil with which the compounds wax-substituted compounds are considered preface-1,377

'alkylated hydroxyaromatic compounds in which the alkyl substituent is derived from Transil oil (a highly refined viscous paraflin base white 011 having a Saybolt viscosity of eighty-two seconds at 100 F. and specific gravity of 0.8498) and from tertiary amyl-phenol.

As will appear from the foregoing description, the oil-improving agents contemplated by this invention are characterized by the general formula III R(T(0H) (N')Yb)n described hereinabove; such chemical compounds or products may also be characterized as oil-miscible alkylated or alkyl-substituted oxyacidyl-amino-aryl hydroxides, it being understood that the term alkyl and alkylated are used herein in a broad sense to include polyatomic or polyvalent as well as monovalent aliphatic radicals or groups and also that the term oxyacidyl is inclusive of organic and inorganic oxyacidyl groups.

Also, as previously indicated, the preferred compounds are those in which a hydrogen of the amino group has been substituted with an oxyacidyl' group of an inorganic acid, preferably the oxyacidyl group of an oxy acid of phosphorus and it is also a further preference that the hydrogen of the hydroxy group of the hydroxyaromatic nucleus be also substituted with such an inorganic oxyacidyl group forming a chelate type compound which is generally more stable.

While the preferred method of preparing the all-:ylated aminohydroxyaromatic compounds in which the amino group is unsubstituted is the nitration and reduction of the corresponding alkylated compound as described above, other methods may be employed for this purpose as follows:

(1) By reduction of alkylated nitroso-hydroxyaromatic compounds (isomeric with quinohe monoximes) with the above reagents.

(2) By coupling alkylated hydroxyaromatic compounds with benzene diazonium chloride and subsequent reduction as above.

(3) By electrolytic reduction of alkylated nitro aromatic compounds.

I (4) By reduction of alkylated nitro-hydroxy aromatic compounds with hydrogen in the presence of a catalyst.

For the formation of the alkylated polycyclic compounds such as amino-naphthols, procedure 2 above is the preferred method.

As will be noted, each of these methods is carried out after alkylation of the aromatic starting material. In method 3, as is well known to those skilled in the art, the aromatic nitro compound is first reduced to aryl hydroxyl amine which under the conditions undergoes molecular rearran'gement into the corresponding aminohydroxyaromatic compound.

SOLUBILITY 6r ALKYLA'IED OXYACIDYL-AMINO- PHENOLS m MINERAL OILS The compounds of the present inventioncan be rendered soluble in mineral oil when prepared from aminophenols containing Q-alkyl substituents. An isoamyl substituent or a wax radical has been found necessary to give the desired solubility. Substituents such as C-alkoxy or organic ester groups or N-alkyl, aralkyl or ester groups have solubilizingvalue, but are not desirable without C-alkyl substituents being present.

C-alkyl substituents are preferred to N-alkyl substituents not only for solubilizing value, but

because of the readiness of preparation and the effectiveness of oxyacidyl metalloid derivatives prepared therefrom.

To demonstrate the effectiveness of compounds or products of the type described above in the mineral oil compositions contemplated by this invention, we have conducted several comparative tests, the results of which are listed below, with representative mineral oils alone and with the same oils blended with various representative nuclear alkylated oxyacidyl-amino-aryl hydroxides.

POUR TEST This series of tests was conducted with a mineral lubricating oil fraction having a Saybolt viscosity of 44.9 seconds at 210 F. and an A. -S. T. M.

pour point 'of +20 F. The alkyl-substituted amino-ary1 hydroxides used were derived from wax-substituted phenolic compounds obtained by condensing chlorwax of substantially sixteen per cent chlorine with the phenolic compound in the ratio of one molecular proportion of phenolic compound to a quantity of chlorwax containing three atomic proportions of chlorine, this condensation product being indicated by "(3-16) in Table I below. The ary1 constituents'of the compounds used in these tests were phenol. The results of these tests are listed below.

TABLE I Action of wax-substituted ozryacidyl-aminophenols as pour point depressants A. S. T. M. Pour test Improving agent o 54% Silicon amide oi wax-amino- F. F. F.

henol (3-16) +20 5 -15 P osphorous amide of the phosphite ester of wax-amino phe-' 1101 (3-16) +20 -5 -20 OPERATION TEST In addition to the foregoing tests we have also made an exemplary test of an oil and an oil blend containing a representative improving agent of the type contemplated by this invention to determine the comparative behavior of the unblended oil and the improved oil composition under actual operating conditions. This test was carried out in a single cylinder CFR engine cooled with a diethylene glycol-water mixture held at a temperature of about 390 F. The engine was operated continuously over a time interval of twenty-eight hours at a speed of. about 1200 R. P. M.. which is equivalent to a road speed of about twenty-five miles per hour. The oil tem'- perature was held at about 150 F. during the test. a

The conditions observed at the end of the test were: (a) the extent to which the piston rings were stuck, (b) the extent to which the slot in the oil rings were filled with deposit, (0) the amount of carbonaceous deposits in the oil, and (d) the neutralization number (acidity) of the oil at the end of the test. The oil used was a lubricating oil stock of 120 seconds Saybolt- Uni- I cated by B5.

1 1 f versal viscosity at 210 F. and the results, which are recorded in Table II below, show a marked improvement in mineral oil composition of the type contemplated by this invention over the oil alone.

In running this exemplary test a comparative run was made with a sample of the blank oil for comparison with the same 011 containing the addition agent. In Table 11 below the blank oil sample is indicated by A5 and the oi1 with the addition agent used in the corresponding run is indiforth in Table 11 below contained the following addition agent in the amount indicated:

B5=1 per cent silicon amide of wax-aminophenol TABLE II Example of the action of an alkylated oasyacidylaminophenol as inhibitor in C..F. R. ring test (28 hours) Ring condition Grams Percent 011 Degrees stuck carbon N. N.

slots filled deposit AL... 360 240 360 360 360 80 90 17.9 2.8 Th...- 0 0 0 0 0 70 7 0 70 14.0 0.0

The improvement produced by the improving agents of the present invention in the viscosity index of mineral oils to which they are added is clearly shown by the illustrative data in the following table: v

TABLE III nols as viscosity index improvers .It will be apparent from the foregoing description that we have developed a new class of mineral oil compositions characterized by the presence in a minor proportion of an alkyl-substituted oxyacidyl-amino-aryl hydroxide as an improving agent. The improved properties obtained and the degree of improvement effected in a particular property may be varied with the various nuclear and oxyacidyl-amino (N) substituents and with the ary1 constituents; also by the degree of alkylationof the aryl nucleus. As to the degree of alkylation, it is important that the aryl nucleus be sufficiently alkylated to provide a final product which is soluble or miscible in the particular mineral oil fraction with which it is to be blended; that is, one which will remain uniformly dispersed in the oil in sufilcient amount to effect the desired improvement. The amount of-improving agent used may be varied, depending upon the mineral oil or the mineral oil fraction with which it is blended and the properties desired in the final oil composition. The alkylated oxyacidyl-aminoary1 hydroxides described hereinmay be used in amounts ranging from 5 per centto five per The last mentioned oil blend as set cent, and in general compositions of the desired improved properties may be obtained with these improving agents in amounts of from /8 p r cent to two per cent. i

It is to be understood that while we have described certain preferred procedures which may be followed in the preparation of the alkylated oxyacidyl-amino-aryl hydroxides used as improving agents in the mineral oil compositions contemplated by this invention and have referred to various representative constituents in these improving compounds, such procedures and examples have been used for illustrative purposes only. The invention, therefore, is not to'be considered as limited by the specific examples given but includes within its scope such changes and modifications as fairly come within the spirit of the appended claims.

This application is a division ofour co-pending application Serial Number 317,122 filed February 3, 1940, now Patent No. 2,280,039 patented April 14, 1942.

We claim:

1. An improved mineral oil composition comprising a, mineral oil having admixed therewith a minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group is replaced by the radical of an oxyacid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

2. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group and the hydrogen of the hydroxyl group are replaced by the radical of an oxyacid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

3. An improved mineral oil composition comalkylated amino-aryl hydroxide in which a hyamino group being attached directly to the aryl nucleus.

6. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group is replaced by the radical of an oxyacid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus and the said oxyacid being selected from the group consisting ofv the oxyacids of phosphorus, sulfur, boron, silicon, selenium and tellurium. g

'7. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group and the hydrogen of the hydroxyl group are replaced by the radical of an inorganic oxyacid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

8. An improved mineral oil composition comprising a mineral oil having admixed therewith a. minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group and the hydrogen of the hydroxyl group are replaced by the radical of an oxyacid of phosphorus which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

9. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group and the hydrogen of the hydroxyl group are replaced by the radical of phosphoric acid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

10. An improved mineral oil composition comprising a mineral oil having admixed therewith a drogen of the amino group is replaced by the radical of an oxyacid of phosphorus which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

5. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group is replaced by the radical of phosphoric acid which remains after removal of an acidic "hydroxyl group therefrom, the said minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a hydrogen of the amino group and the hydrogen of the hydroxyl group are replaced by the radical of phosphorous acid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

11. -An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible nuclear alkylated amino-aryl hydroxide in which a, hydrogen of the amino group and the hydrogen of the hydroxyl group are replaced by the radical of silicic acid which remains after removal of an acidic hydroxyl group therefrom, the said amino group being attached directly to the aryl nucleus.

, ORLAND M. REIFF.

HOWARD D. HARTOUGH. 

